Molecular Phylogenomics and Population Structure of .

is an oomycete that was first isolated from soil, water, and tree foliage in mixed Douglas-fir-tanoak forests of the U.S. Pacific Northwest (PNW).

Functional analysis of RXLR effectors from the New Zealand kauri dieback pathogen Phytophthora agathidicida.

New Zealand kauri is an ancient, iconic, gymnosperm tree species that is under threat from a lethal dieback disease caused by the oomycete Phytophthora agathidicida. To gain insight into this pathogen, we determined whether proteinaceous effectors of P. agathidicida interact with the immune system of a model angiosperm, Nicotiana, as previously shown for Phytophthora pathogens of angiosperms.

Contrasting the Pathogen Loads in Co-Existing Populations of and in Douglas Fir Plantations in New Zealand and the Pacific Northwest United States.

The emergence of as a foliar pathogen of Douglas fir in New Zealand and the Pacific Northwest United States has raised questions about its interaction with the widespread Swiss needle cast (SNC) disease. During Spring 2017, we repeatedly sampled 30 trees along an environmental gradient in each region and 292 additional trees in a longitudinal transect to assess the epidemic and the association between and , which are causal agents of SNC. Both pathogens were consistently more abundant in the host's exotic environment in New Zealand.

Modelling the key drivers of an aerial Phytophthora foliar disease epidemic, from the needles to the whole plant.

Understanding the epidemiology of infectious diseases in a host population is a major challenge in forestry. Radiata pine plantations in New Zealand are impacted by a foliar disease, red needle cast (RNC), caused by Phytophthora pluvialis. This pathogen is dispersed by water splash with polycyclic infection affecting the lower part of the tree canopy.

Genome sequencing of oomycete isolates from Chile supports the New Zealand origin of Phytophthora kernoviae and makes available the first Nothophytophthora sp. genome.

Genome sequences were generated for six oomycete isolates collected from forests in Valdivia, Chile. Three of the isolates were identified morphologically as Phytophthora kernoviae, whereas two were similar to other clade 10 Phytophthora species. One isolate was tentatively identified as Nothophytophthora valdiviana based on nucleotide sequence similarity in the cytochrome oxidase 1 gene.

Phytophthora pluvialis Studies on Douglas-fir Require Swiss Needle Cast Suppression.

Phytophthora pluvialis is associated with early defoliation and shoot dieback in Douglas-fir in Oregon and New Zealand. In 2013, P. pluvialis was described from mixed tanoak-Douglas-fir forests in the Pacific Northwest and concurrently recognized as the main causal agent of red needle cast (RNC) in New Zealand radiata pine plantations.

The emerging science of linked plant-fungal invasions.

Contents 1314 I. 1315 II. 1316 III.

Foliar phosphite application has minor phytotoxic impacts across a diverse range of conifers and woody angiosperms.

Phytophthora plant pathogens cause tremendous damage in planted and natural systems worldwide. Phosphite is one of the only effective chemicals to control broad-scale Phytophthora disease. Little work has been done on the phytotoxic effects of phosphite application on plant communities especially in combination with plant physiological impacts.